We’ve put together a guide that details everything you need to know about LEV Extraction System Design to help you understand the different elements of a local exhaust ventilation (LEV) system when sourcing your preferred LEV installer.
What is a LEV System?
Under Regulation 7 of the Control of Substances Hazardous to Health (COSHH) Regulations 2002, employers are required to implement control measures to protect employees from exposure to hazardous substances. Local Exhaust Ventilation (LEV) systems are an engineering control measure that’s designed to remove (or reduce) the risk of airborne contaminants from the worker’s breathing zone.
LEV systems are typically constructed of four main components, these include:
- A hood to capture, to contain the airborne contaminants, at-source
- A filter (or filtration units) depending on the contaminants the system there is to control, such as dust particles
- A fan (or air mover) to draw the contaminants from the breathing zone through the system and away from the workplace
- An exhaust stack to safely discharge the contaminants to the atmosphere
In between these four main components, the captured air is conveyed through the system through specifically sized ductwork.
The Importance of Good LEV Extraction System Design
It is integral that LEV systems are designed and specified correctly to capture and convey contaminants correctly, and to the recommended standards. In many cases, LEV systems are incorrectly sized and subsequently fail to control substances adequately. This, in turn, defeats the objective of assembling the system in the first place. Extraction systems should be methodically designed, taking into account the four key components to calculate the air volumes, velocities and pressures to effectively control exposure to harmful dust and fumes from the workplace.
LEV systems should be designed by a competent P602 LEV system design engineer. This qualification certifies that the engineer is knowledgeable in the methodology, theoretical and has practical experience to design basic LEV systems for controlling occupational exposures to hazardous substances. They’ll be knowledgeable in calculating the performance calculating the necessary contaminants, such as dust (including fine or coarse dust), fumes, vapours, gases and mists, effective capture hood design and sizing appropriately sized fans.
In addition, system design engineers will be familiar with HSE’s HSG 258: Controlling Airborne Contaminants at Work: A Guide to Local Exhaust Ventilation (LEV) guidance document, which details the minimum requirements for designing, installing and commissioning a LEV system.
Capture Hood Design
The hood is considered to be the key component of a LEV system. If a poor capture hood method has been specified, then this puts the whole LEV system at risk of being ineffective and potentially risk not adequately controlling airborne contaminants effectively.
When designing the extraction system, the requirement of the worker and the working process should be considered. The capture hood should be suitable and enable the worker to complete their role whilst not being exposed. There are various kinds of air capture hoods available and these are categorised into three groups;
These typically surround the working process, encapsulating the source and containing the risk. These contain contaminants being released into the broader working environment. An example of an effective enclosing hood is Fume Cabinets.
These typically draw the contaminants into the system and away from the worker. The contaminants are generally produced outside of the hood. An example of an effective capture hood is a Dust Extraction Arm or Hose Extraction Arm.
These typically work in a similar way to capturing hoods, with the exception that the process is producing sufficient energy (heat or speed) to make its own way to the hood. An example of an effective receiving hood is Fume Canopies.
LEV Extraction System Testing
LEV testing is a process whereby an extraction system’s airflows, pressures and velocities are measured against its initial benchmarked performance levels. LEV equipment should be thoroughly examined and tested at least once every 14 months. Tests of LEV systems should be in good working order and in good repair.
Request your FREE LEV Site Assessment Today!
We’ll call to arrange a convenient time and date to visit your site. We’ll analyse your working processes, assess the substances used and the contaminants generated. We’ll work out how best to control the dust and fume in a way that’s in line with your COSHH risk assessment. Next, we’ll design you a comprehensive LEV system that adheres to HSG258 guidance and send this you to via email.
We’ll do all this to ensure we fully understand your dust and fume extraction requirements and help you to provide a pollution-free workplace!
This is an amazing service we do for thousands of businesses throughout the UK and Ireland every year. We work with such a wide variety of industries, from manufacturing, industrial, woodworking, pharmaceutical and automotive workshops to schools, colleges and military establishments.
Request your FREE, no-obligation LEV site assessment today!
An Inventory of Successfully Completed Installations
Over our 20 years in business, we’ve helped thousands of businesses provide pollution-free workplaces. We’ve provided comprehensive LEV design and specification, installation, certification services for all kinds of processes and industries. Browse some of our favourite projects in our Case Studies section.
Why Choose Auto Extract Systems?
Auto Extract Systems is the UK’s leading LEV company. Over the last 20 years, we’ve helped thousands of businesses create dust and fume free workplaces. We have steadily been building and diversifying into new industries to help businesses provide pollution-free workplaces with comprehensive LEV (local exhaust ventilation) systems. Our team of P602 qualified LEV system design engineers have over 80 years of combined experience, the know-how, and the ability to specify comprehensive LEV systems to help your business meet HSE’s HSG258 guidance.
As experts in all things LEV, we can help your business become COSHH (Control of Substances Hazardous to Health) Regulation 2002 compliant with a tailored LEV solution. We provide comprehensive design, installation, testing, maintenance and remedial works services across a range of industry sectors. Find out more about us here.